Feank c



(No Model.)

I. 0-. WATKINS.

TELEPHONE TRANSMITTER.

No. 369,379. Patented Sept. 6, 1887.

QXHI M case a her, Wullinglnn. D. C

UNITED STATES PATENT @rrrce.

FRANK C. WATKINS, OF PHILADELPHIA, PENNSYLVANIA, ASSIGNOR, BY MESNE ASSIGNMENTS, TO THE UNITED STATES KROTOPI-IONE COMPANY,

OF NEW YORK, N. Y.

TELEPHONE TRANSMITTER.

EPECIFICATION forming part of Letters Patent No. 369,379, dated September 6, 1887.

Application filed Dccembcrfli, 1886. Serial No. 222,476. (No model.)

To aZZ whom it may concern.-

Be it known that I, FRANK G. WArniNs, a citizen of the United States, residing at Philadelphia, in the county of Philadelphia and 5 State of Pennsylvania, have invented certain new and useful Improvements in Telephonelransmitters; and I do declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in K the art to which it appertains to make and use the same, reference being had to the accompanying drawings, and to the letters and figures of reference marked thereon, which form a part of this specification.

[ My invention has relation to transmitters for telephones, and the object is to provide a device of this kind for transmitting an intermittent direct current on the main line, so as to dispense with an induction-coil, and thereby save the system from the annoyance due to induction; and to these ends the novelty consists in a vibrating diaphragm provided with a rearwardly-projecting face-plate, against the face of which rests a series of conducting spheres supported and contained within a funnel-shaped cup, which is suitably suspended parallel to and in close proximity to said face-plate, as will be hereinafter more fully described, and particularly pointed out in the claim.

In the accompanying drawings the same letters of reference indicate the same parts of the invention.

Figure l is a diametrical section of my improved form of transmitter. Fig. 2 is a rear elevation of the same. Figs. 3 and 4 are modiiications thereof.

A is an annular ring which forms the frame of the device, and secured to the front thereof by a flange, a, is an openended hood, l3, having a bottom, I), provided with a central orifice, Z), the hood, bottom, and flange being preferably made integral. Suspended parallel with and immediately in the rear of the bottom of the hood is a diaphragm, G, to the center of which is secured a face-plate, D, by a screw, 0. Mounted in front of this faceplate so that its open end is approximately covered by the face is a conical metallic cup,

E, whichcontains a number of small carbon or other electricallyconducting spheres, e, loosely contained therein, so as to form a connection between the face-plate and the interior of the metallic cup. The periphery of this cup has a series of integral cars, a, and beginning from the adjusting-screw F a wire runs through one of these cars, thence around a screw or stud, 23, through another car, then around a second stud, 7;, then through the remaining ear and back to the starting-point on the screw F, which is then adjusted so as to produce considerable tension on the wire '22, which suspends the conical cup ina comparatively rigid yet elastic position in front of the face-plate, as above set forth.

G represents the linewire, which is connected to the diaphragm from whence the current is conducted to the face-plate, carbon spheres, conical cup, itssupporting-wires,and thence to the ground-wire H.

The peculiar manner of mounting the cup and of conducting the current from it to the diaphragm, through the medium of the movable spheres, enables me to produce the most satisfactory results, and the instrument, after being once set up, requires no further adjusting whatever.

In the modifications shown in Figs. 3 and 4. the number of conical cups are increased to correspond to the distance or length of the line, as on very long-distance lines it is desirable to increase the battery, and consequently amplify the transmitting principle.

Having thus fully described my improved transmitter, what I claim is- In a transmitter, a series of conducting-receptacles and a diaphragm, in combination with a series of conducting-spheres loosely contained within said receptacles and forming a connection between said receptacles and diaphragm, as set forth.

In testimony whereof I affix my signature in presence of two witnesses.

FRANK O. WAIIKINS.

W'itnesses:

H. J. ENNIS, J. MoNAMnn. 

